I have these books on my shelf, the first is British and it's date's on the 3rd page Feb 1949. The Reference book is probably 1946, I have 2 copies, last year I was given a complete set of these Reference Manuals all in their original boxes.

If you compare the two you'll see products mentioned in the British publication that were never available in the US, also in the UK D72 (dektol) is listed only as a film & plate developer while it's also a print developer in the US books. In practice Kodak Ltd (UK) sold D163 as their main print developer yet it's not listed in the US publication, theres a few others as well.

There were at least 2 editions of the US version of the chemical formulas, and the film, lens and filter book was published in 3 booklets here in the US. I have all of them except the lens book. The formula and filter books are very useful to me. There is a 1940s boo that was published by an outside firm that also contains much of this data but covers companies other than EK. For example, this book contains the entire formula set for processing Dufay color film.

I hope that we do not lose this technology as people throw out old things.